Wolfe had the patient do a second breathing test when she arrived. The first, done a year earlier, was completely normal. This one wasn’t. The changes were subtle but real. The amount of air she could get out in a forced exhalation was less than it was when she was tested the year before.
Could this be some tough form of asthma, considering that the usual medications hadn’t helped? Or was this some kind of slow-growing lung infection? There is a bacterium, a distant cousin of tuberculosis, called mycobacterium avium complex (MAC), which can cause coughing, shortness of breath and phlegm production. It is rare but is most often seen in older women. It’s thought to be caused, at least in part, by a woman’s reluctance to cough and clear mucus and other secretions from her lungs and airways. It’s called Lady Windermere syndrome, after a character in an Oscar Wilde play. Lady Windermere is a very proper young woman of the Victorian era who presumably would be too well behaved to cough or show other signs of illness. The nodules in the patient’s lungs that showed up on her CT scans could be the earliest sign of such an infection.
Wolfe ordered a series of tests to look for each of these disorders. He also ordered another CT scan of her lungs — her third — to see if the nodules had changed in the months since her last scan.
Flipping Through CT Images
Dr. Emily Tsai, a radiologist who specialized in imaging of the chest at Stanford University School of Medicine, sat in a darkened room looking through the more than 300 images of the patient’s new CT scan. Although you could look at each image separately, it is often more useful to view them sequentially, like a flipbook in which drawings turn into moving pictures. In this way the radiologist can take a three-dimensional tour through the examined chest, following the blood vessels and airways as they appear, progress and end in this animated show.
Tsai had developed her own system: First she would look through the image as a whole, seeking obvious abnormalities and getting the lay of the land. She compared the newest views with the earlier images. Then she would focus on the part of the lung where there were reported or expected abnormalities. In this woman’s case, she looked where the reported nodules had been located. There was a little scarring — where the narrow treelike branches of the airways got stretched out and baggy in what was called bronchiectasis. That could certainly go along with a diagnosis of MAC infection. Then she took another careful look at all the other parts of the chest. In images like these, filled with so much information, a radiologist has to review the images as closely as possible. No one can see everything. Maybe artificial intelligence will get there one day. But she tried to see what was there.
As she scrolled to the very top of the image, she saw something that seemed a little abnormal. The trachea, the breathing tube that connects the upper airways of nose and mouth to the lower airways of the lungs, seemed to be strangely narrow near the top. The narrowing was less than a centimeter long before it widened out to the normal diameter. Tsai found the same narrowing in the other CTs and reviewed the reports to see what previous radiologists made of this finding. Neither mentioned it at all, perhaps because it looked like a tiny puddle of secretions. The key was that it was the same in all three exams. Secretions move around. This narrowing, whatever the cause, did not. Tsai wasn’t sure what to make of it, but in her report she suggested that it could be contributing to the patient’s symptoms.
When Wolfe saw the radiologist’s report, he realized that this narrowing of the trachea could be the cause of all of the patient’s symptoms. How had it happened? She had never needed a breathing tube placed in her trachea during surgery or a serious illness — that was the most common cause of this type of unusual finding. Wolfe ordered further tests to look for possible infections or inflammatory causes of the narrowing. All were unrevealing. It wasn’t MAC or any of the other causes Wolfe could think of or test for. Ruling out everything gave him her diagnosis: She had idiopathic subglottic stenosis. Idiopathic meant that the cause was unknown. Subglottic identified the location in the trachea, just below the vocal cords. It is a rare and poorly understood disorder seen almost exclusively in middle-aged women. Because her narrowing was causing her to be short of breath, the stricture needed to be opened.
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